The U.S. military continues to investigate what might happen if you were zapped by one of its microwave weapons. Active denial technology, as the military calls it, uses 94 GHz millimeter waves (MMW) to induce pain by heating the skin. The Marine Corps says it’s like touching “an ordinary light bulb that has been left on for a while” —in fact, it’s just a “harmless energy beam,” according to the marines. Not everyone agrees.